Petts Wood: Petrol in a Diesel Car? How Worried to Be
Far less than you probably are, if it has not been started. Everyone around Petts Wood starts with "have I ruined it?", and the honest answer is normally no: petrol resting in your tank of any diesel stays harmless until priming, cranking or driving draws it into your fuel system. Keep it that way: leave your motor off and phone Petrol in Diesel. Below, you will find what petrol actually does inside a diesel, how far it may have gone, and how to stop it happening to you again.
Inside the engine: what petrol in a diesel really does
Two tasks fall to diesel on its journey round a motor. Before it ignites, it protects — then it burns. The high-pressure fuel pump and the fuel injectors are built to very fine clearances, and the diesel passing through them is what keeps those surfaces from grinding against each other.
Petrol handles the first job badly and the second not at all. Being less viscous than diesel, petrol strips out the protection a fuel system needs, leaving a pump running on the blend to wear itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the clattering.
Together, those leave the shape of the issue plain. The harm is done by movement, not by contact. All a tank with petrol in it amounts to is a fuel problem. Whatever a worn pump sheds travels on, borne by your fuel, into the fuel injectors downstream, which is why a pump that has worked on that petrol is where a mechanical fault starts.
Petrol in a diesel around Petts Wood: how serious is it? Four situations
The best case there is: filled up, never started. Only your tank has petrol in it, and so the task is draining the tank and cleaning the fuel system where the car sits. This scenario can only really take place at a forecourt: anywhere else, your car got there by being driven.
The ignition turned on, or a short start. With your system primed, your lines and filter now contain petrol that has come from your tank. Still normally straightforward: drain, flush, and your filter dealt with.
Driven a couple of miles. Now your pump has spent these miles labouring on thinned fuel. Tank, lines, filter, then clean fuel put through the entire circuit: that's the work, and the way the vehicle was driven counts as much as the miles. A school run to St James' Roman Catholic Primary School is one matter. Very different a second time: a trip to London, under 15 miles away, or some mileage on the M25, under 5 miles from Petts Wood, where your engine kept running hard.
Driven on until it complained — rattling, smoke, a lumpy idle, a dead throttle. What you are hearing is the motor signalling fuel that no longer runs like diesel. Whether it is the verge on Frankswood Avenue, a lay-by or a side street, stop there then leave it. Lasting damage is very rare when a vehicle is stopped early, and the fuel drain and flush-through that still come first take care of it.
Petts Wood people and that petrol in a diesel myths they hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Topping up takes out nothing; it gives you a bigger tank of the same mixture. The assumption behind that advice — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. At higher pressure, through smaller components: that's how a newer diesel moves its fuel, so the lubrication matters more, not less.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. Diesel in a petrol motor generally leaves a motor that won't run: the driver stops, and so does the harm. Feed petrol to a diesel and it normally starts, idles and pulls away like nothing happened — all while its pump is wearing. Running is not the same as fine.
An old fix for a distinct fault lies behind this one. Myth: "Add some two-stroke oil and drive the car home." None of what petrol thinned gets put back by it — and afterwards, the tank still holds the petrol.
If your engine has been run, part of the petrol is in the filter and the lines, not your tank — and your next start sends it straight back through your pump. So the myth "drain your tank yourself and you're sorted" does not hold. Besides, petrol cleared into a can by the road is genuinely hazardous.
How petrol ends up: petrol in a diesel
It's seldom carelessness, and nobody does it on purpose. The forecourt makes it simple: the petrol nozzle is the narrower of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle mostly won't go into a petrol motor at all. So the mistake runs one way.
When routine and the vehicle stop matching, it happens. A motor that is new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps arranged differently. Filling up in a rush en route to the nearest station, with a train to catch. Precisely the moment it takes place: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. Throw in rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
Next time you fill up in Petts Wood: preventing petrol in a diesel
- The label is what matters, so check the petrol pump instead of the colour: in the UK unleaded handles are normally green and diesel black, but not on each forecourt.
- Plenty of cars state the fuel type inside your filler flap or on the cap, so check it on your first fill in a vehicle you don't know.
- A coloured fob or a sticker on your diesel's key does more than any amount of intending to remember, in a home with one of each.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump. It seems daft and it does the trick.
- Tuck the phone away. This is an easy mistake to make whilst you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to reject a petrol nozzle, and add-on devices exist for the rest. Treat it as a safety net, then keep checking the pump.
- Stop the moment you realise. Less petrol inside the tank means a weaker mixture. It does not change what to do next, which is still not to fire it up.
Petts Wood: already put petrol in a diesel?
The order of things is brief, then. Never fire it up, and do not switch the ignition on. If you're still at the forecourt — Shell or anywhere else — ask the attendants to help you push the vehicle away from the pump. Next, 0333 366 0103. We will ask what was put in, roughly how much, and if it's been run.
Corrosion and deposits form the trouble with AdBlue, whereas petrol means lost lubrication. So if it was AdBlue, say so — and see its own Petts Wood page.
Petts Wood petrol in a diesel tasks: why one costs more than another
The four situations above are four separate tasks, so no single price for this would be fair. The scenario itself does most of the work of moving your cost. Beyond that it's the share — how much petrol got in against how much that tank takes — and after that where the car is and whether a technician can reach it safely.
What was put in, how much, and whether it's run — three queries our engineers ask before costing, not after, for precisely that reason. A range turns into a straight figure once the answers are in.
About Petts Wood
Petts Wood is a suburban area in south-east London, situated near the River Shuttle at an elevation of around 85 metres. Petts Wood lies close to the neighbouring areas of Southborough, Broom Hill, and Crofton, and is approximately 11 miles from central London. Petts Wood is characterized by its predominantly semi-detached housing stock and a population of around 5638 residents. Petts Wood forms part of the wider London urban area, with easy access to the city centre.
Across Greater London and around Petts Wood: fuel drain cover
Petts Wood sits in the BR postcode area, and our teams that answer petrol in diesel jobs there work the places near it as well — Southborough, Broom Hill and Crofton among them. The car doesn't need to come to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
In Petts Wood and still at the petrol pump?
In that case, you couldn't be in a better spot. Leave it turned off, then ring.